A crumb of a clue on epidemiology

[Murph]

Well! its a delight to come back here and see the thing I offered as "a feint, an opening gambit, a prompt" be taken with such goodwill! A wonderful contrast to the reddit crowd.

Here's the summary as i see it:
1. I looked at the map of google searches for me/cfs (strong in UK and Norway) and asked a question: what if there was signal on prevalence mixed in with signal on awareness. For a long time, I couldn't figure out any way to untangle the two.

2. I wondered using variation in English heritage within the US could help answer the question. If the pattern in England and Norway was just awareness you'd have no obvious reason to find any correlation within the USA.

3. I found a clue that correlation was not zero within the USA the case of England. I emphasised this is not proof of anything, but it perhaps introduces a teeny tiny wobble to the null case of equal prevalence worldwide.

4. @forestglip took the ball and ran with it, further and far more rigorously than I had. Honestly, further and far more rigorously than I dared hope. Their work successfully reduced two of the kinds of uncertainty: there really does seem to be a correlation between English heritage and searches for the illness, and income or English-speaking is not the confounder.


5. Three types of uncertainty remain reasons why this is probably still nothing.

5.1 English, in the UK context, is a diluted category (Saxons, Normans, Celts). Let alone in the USA where English migration was some time ago!

First thought is, does 'English' really exist?

5.2 Google trends data certainly doesn't only capture what it intends to capture, nor can we be sure it deals with foreign languages as well as it claims.

Edit: Oh ha. Mississippi's searches for MS are extremely high because the state abbreviation for Mississippi is MS.

5.3 We have no certainty searches correlate with prevalence - although it obviously can, it's not prima facie ridiculous - and forestglip has done some work to prune off some of the most obvious other explanations.

There isn't a very strong correlation between the ME/CFS search trends and speaking English at home:

6. So there *seems* to be a peculiar thing going on here, and one explanation *could* be that British/Celtic heritage correlates with MECFS. I'd say my confidence in the conclusion of Son et al has gone from maybe 55% before I did this analysis to maybe 50%.

"The total prevalence reported for Western and Asian populations were comparable."

Not a big shift, still lots of uncertainty. But in the research void we inhabit, getting even tiny probabilistic clues for free from existing public datatsets is worth something. As me/cfs science blog did with their immune work this week, emphasising what we don't know is important, and I don't think we know for sure that me/cfs hits all people equally.

Perhaps other clues will come forth and show all this to be a red herring. Perhaps other clues (HLA?) will suggest there's something going on.

 

[MrMagoo]

I think it’s an interesting side quest to think about.

According to my Ancestry data I’m hardly English though, very Celtic but then again I am a little bit Norwegian, so that must be who is to blame! I can’t remember which parent that came from, I must check.

I thought DecodeME selected people of a particular background, I know my data was used despite being mixed race African.

 

[Kitty]

5.1 English, in the UK context, is a diluted category (Saxons, Normans, Celts).

Yep. When you've added in the descendants of incoming medieval Scandinavians, 19th / 20th century eastern European Jews, etc, it becomes clear the category 'white English' includes most of northern Europe.

I agree there could be something in this, but we need to remember it's not really feasible to draw clear genetic boundaries on maps or in time. Too many people have been annoyingly resistant to staying put for too long.

 

[MrMagoo]

I think this is interesting also because it’s got a lot of possible cultural bias such as certain groups having preference for using ME/CFS as the search term, or increased media and campaigning in the UK and USA.

One interesting comparison might be Australia - a lot of UK and Irish ancestry, majority English speaking population, I wonder what their results are like?

 

[Murph]

I think this is interesting also because it’s got a lot of possible cultural bias such as certain groups having preference for using ME/CFS as the search term, or increased media and campaigning in the UK and USA.

One interesting comparison might be Australia - a lot of UK and Irish ancestry, majority English speaking population, I wonder what their results are like?

• Australia has many fewer states with quite uneven populations; only five states have more than a million people. the chance of getting signal in such a small sample is less. I've obviously shown willingness to listen out for signal amid noise, but I have my limits!
• Also there's perhaps less diversity than in the US, and the heritage mix is, historically, more evenly distributed. There's lots of English heritage people everywhere!
• And lastly the bushfire response service in South Australia gets a lot of searches each summer and it is known as the Country Fire Service (CFS), which rather ruins the results for that state. Perhaps you could get the data over winter in SA and normalise but I'd be nervous.

But I bet tehre's other ways we could slice the onion .Going back to @jmaciuch's observation about people guessing their heritgae based on their last name, I wonder if that could offer another low-cost approach using exitsing data.

Anyone with access to a public list of pwme coudl run a quick analysis of surnames. You might expect Smith to be ahead of Ferrero and Kowalski ... but then you could perhaps compare to population rates. Just an idea!

 

[Murph]

Also, just for context I should share a quote form the paper - Systematic review and meta-analysis of the prevalence of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) - I have been referencing.

They characterise an idea related to the one I'm wondering about as an outdated one.

It is well-known genetic background and living environment are important factors in the development or progression of diseases [48]. CFS/ME was once considered a disease of the middle to upper classes that was mostly prevalent in the Caucasian population [49], although other studies have suggested that members of minority groups and lower economic classes are more prone to CFS/ME due to psychosocial and environmental risk factors such as lack of adequate nutrition, limited access to healthcare, and work-related stressors [16, 50–52]. In this respect, it is of interest that some studies from different countries showed similar prevalence rates in similar settings; i.e., when the CDC-1994 was used with a medical test for a community-based general population, similar results were found for Nigeria (0.28% for CFS, or 0.68% of CFS-like), the U.S. (0.60% and 0.42%), and Korea (0.61%) [50, 53–55] (Table 2).

It's appropriate to be cautious about reviving old ideas. But we should absolutely get the defibrillators out if those ideas are true!

On my list of disclosures should perhaps also be my own heritage, most of my ancestors apparently grew up between Devon and Penwith (England), or near Cork (Ireland)! Perhaps it easy to look around, see all the British people in these forums and jump to conclusions.

 

[Felis Catus]

I was wondering what was the reason for countries with no data. Is it that it was too laborious to include them or not enough hits?

 

[MrMagoo]

Isn’t there quite a strong pwME community in South Africa? Interesting to see the heritage split between white European heritage and black African.